JEFFERSON CITY, Mo. (AP) — U.S. senators from seven Missouri River states are asking the Government Accountability Office to examine this summer’s heavy flooding throughout the river basin.The request was supported by 13 senators who are part of the Missouri River Working Group. The group includes senators from Iowa, Kansas, Missouri, Montana, Nebraska, North Dakota and South Dakota.The senators want the GAO to review several issues, including whether the Army Corps of Engineers followed its master manual for managing the Missouri River and what role meteorological forecasts played. They also want to know if environmental concerns, such as protecting endangered species, influenced flood-control efforts.